A conducting terminal of a conventional electrical connector generally fixes a tin ball in a pre-soldering manner, that is, first the tin ball is soldered to the tail portion of the terminal, and then the tin ball is soldered to a circuit board. This practice involves many soldering procedures, thereby increasing costs.
In order to solve the foregoing problem, an electrical connector including a terminal for clamping a tin ball by using a clamping arm without the need of pre-soldering occurs in the industry. As disclosed in U.S. Pat. No. 8,277,230, an electrical connector includes an insulating body. Multiple receiving holes run through the insulating body. Multiple conducting terminals are disposed in the receiving holes. Multiple protruding blocks are disposed on a lower surface of the insulating body and located at the periphery of the receiving hole, where two adjacent protruding blocks are located at two opposite sides of the receiving hole. The conducting terminal includes a base portion. An elastic arm extends upward from the base portion. A contact portion is disposed at an end of the elastic arm. Two soldering arms extend downward from the base portion, and a gap exists between the two soldering arms and is used for mounting a tin ball. Each of the soldering arms has a bended extending arm and a clamping end extending from the extending arm. When the tin ball is loaded between two clamping ends, the two clamping ends clamp the widest portion (that is, the portion at the diameter) of the tin ball, so that the tin ball is stably clamped by the two clamping ends. Meanwhile, the two opposite protruding blocks are disposed around the periphery of each of the receiving holes. The two clamping ends and the two protruding blocks jointly urge the tin ball, thereby limiting the tin ball in transverse and longitudinal directions, and ensuring the location of the tin ball. Compared with the conventional manner of pre-soldering a tin ball, the foregoing manner of clamping the tin ball by using the clamping end of the conducting terminal saves the soldering process, and is more simple and convenient in manufacturing.
The two protruding blocks and the two clamping ends respectively urge the tin ball in two directions. A gap exists between the two protruding blocks, and the two clamping ends are located in the gap, and can be deformed in the gap. When the tin ball enters a space between the two clamping ends, the soldering arm is propped by the tin ball. Due to a force to which the soldering arm is subject, the soldering arm is not only propped open in a clamping direction, but also may be propped in a direction perpendicular to the clamping direction. In this case, the two clamping ends may be deformed in the gap in the direction perpendicular to the clamping direction. That is, the two clamping ends are dislocated or deflected, so that a distance between the two clamping ends is greater than the diameter of the tin ball, the two soldering arms cannot clamp the widest portion of the tin ball, the tin ball easily falls off, and therefore the soldering quality of the electrical connector cannot be ensured.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.